Dirt & Development

I have a paper with a former Ph.D. student on the difficulties of agricultural production in tropical sub-Saharan Africa.  It has been an interest of mine ever since I first read Jared Diamond’s Guns, Germs, and Steel and later Jeffrey Sachs’ papers on the development difficulties of tropical climates.  So I was intrigued when I saw that the European Union’s Institute for Environment & Sustainability has just published a Soil Atlas of Africa and it is available online. It uses computer mapping techniques to create stunning illustrations of the the type of soil problems that Africa suffers from.  Below is a picture from the cover of the atlas:


While the maps are incredible, the message is pretty sobering.  Among other things, the atlas finds that:

1. “While Africa has some of the most fertile land on the planet, the soils over much of the continent are fragile, often lacking in essential nutrients and organic matter.”

2. “Aridity and desertification affects around half the continent while more than half of the remaining land is characterised by old, highly weathered, acidic soils with high levels of iron and aluminium oxides (hence the characteristics colour of many tropical soils) that require careful management if used for agriculture.”

3. “Soils under tropical rainforests are not naturally fertile but depend instead on the high and constant supply of organic matter from natural vegetation and its rapid decomposition in a hot and humid climate. Breaking this cycle (i.e. through deforestation) quickly reduces the productivity of the soil and leaves the land vulnerable to degradation”

4. “In many parts of Africa, soils are losing nutrients at a very high rate, much greater than the levels of fertiliser inputs. As a result of rural poverty, farmers are unable to apply sufficient nutrients due to the high costs of inorganic fertilisers or from a lack of farm machinery (Africa has the lowest use of industrial fertilisers in the world). Traditional practices, such as long fallow periods that improve nutrient budgets and restore soil fertility, are difficult to implement due to the increased pressures on land and changes in land tenure that restrict traditional nomadic lifestyles.”

Yikes, sobering indeed.

A New Database on Educational Quality

I frequently have my undergrad and grad students read Bill Easterly’s excellent book, The Elusive Quest for Growth: Economists’ Adventures and Misadventures in the Tropics.  They are often a bit depressed after reading the chapters on growth, noting how little we seem to know about growth in the real world.  It is the education chapter, however, which really gets to them.  In it, Easterly points out what has been known for ages but is rarely mentioned in print (see Lant Pritchett’s “Where has all the education gone?” for a refreshing exception), namely, that education is not positively and significantly related to economic growth for most samples.  Sometimes you can find a weakly positive t-stat in a sample of OECD countries, but you are lucky if you merely find zero correlation (instead of a negative and significant) in the developing world.

I reassure students by telling them that one of the problems with these regressions is that we are trying to measure human capital without any ability to adjust for quality across countries. 8 years of education in Switzerland may not be equivalent to 8 years of education in Guinea-Bissau (see this new NBER working paper for a truly depressing look at this country’s educational woes).

We have some measures of quality, but not usually enough to use in a panel of countries.  A new working paper called “A New International Database on Education Quality: 1965-2010” by  Nadir Altinok, Claude Diebolt, and Jean-Luc Demeulemeester seeks to fill this gap by creating a new database of educational quality for 103 countries from 1965 to 2010.  Their approach is innovative in that it “includes regional student achievement tests and intertemporal comparable indicators.” 

Check out the Figure below (it’s small so click on it for a larger view) for an idea of how primary school quality differs across countries.  They find that Asian countries have the highest average primary school quality (although I do question how Kazakhstan can be scoring so highly), there is a lot of variance in the Arab states, and that Sub-Saharan African countries as a whole rank relatively low (although again there is a fair amount of variance).  From this figure at least, it looks like Mauritania has its work cut out for it.